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Desert Ants (desert + ant)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

Visual experience and age affect synaptic organization in the mushroom bodies of the desert ant Cataglyphis fortis

DEVELOPMENTAL NEUROBIOLOGY, Issue 6 2010
Sara Mae Stieb
Abstract Desert ants of the genus Cataglyphis undergo an age-related polyethism from interior workers involved in brood care and food processing to short-lived outdoor foragers with remarkable visual navigation capabilities. The quick transition from dark to light suggests that visual centers in the ant's brain express a high degree of plasticity. To investigate structural synaptic plasticity in the mushroom bodies (MBs),sensory integration centers supposed to be involved in learning and memory,we immunolabeled and quantified pre- and postsynaptic profiles of synaptic complexes (microglomeruli, MG) in the visual (collar) and olfactory (lip) input regions of the MB calyx. The results show that a volume increase of the MB calyx during behavioral transition is associated with a decrease in MG numbers in the collar and, less pronounced, in the lip. Analysis of tubulin-positive profiles indicates that presynaptic pruning of projection neurons and dendritic expansion in intrinsic Kenyon cells are involved. Light-exposure of dark-reared ants of different age classes revealed similar effects. The results indicate that this structural synaptic plasticity in the MB calyx is primarily driven by visual experience rather than by an internal program. This is supported by the fact that dark-reared ants age-matched to foragers had MG numbers comparable to those of interior workers. Ants aged artificially for up to 1 year expressed a similar plasticity. These results suggest that the high degree of neuronal plasticity in visual input regions of the MB calyx may be an important factor related to behavior transitions associated with division of labor. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 408,423, 2010 [source]

Spatial patterns, temporal variability, and the role of multi-nest colonies in a monogynous Spanish desert ant

ECOLOGICAL ENTOMOLOGY, Issue 1 2002
Xim Cerdá
Abstract 1.,The colonies of the Spanish desert ant Cataglyphis iberica are polydomous. This study describes the temporal and spatial patterns of the polydomy in this species at two different sites, and presents analyses of its role in reducing the attacks of the queen over sexual brood, and in allowing better habitat exploitation. 2. The spatial distribution of nests was clumped while colonies were distributed randomly. Mean nearest neighbour distance ranged from 3.4 to 7.0 m for nests and from 12.3 to 14.1 m for colonies. Distance of foragers searching for food varied among nests: mean values were between 6.1 and 12.6 m. 3. At both sites, the maximum number of nests per colony occurred in summer, during the maximum activity period of the species. Colonies regrouped at the end of this period but overwintered in several nests. 4. Nest renewal in C. iberica colonies was high and showed great temporal variability: nests changed (open, close, re-open) continuously through the activity season and/or among years. The lifetime of up to 55% of nests was only 1,3 months. 5. Polydomy in C. iberica might decrease the interactions between the queen and the sexual brood. In all colonies excavated just before the mating period, the nest containing the queen did not contain any virgin female. Females were in the queenless nests of the colony. 6. The results also suggest that polydomous C. iberica colonies may enhance habitat exploitation because foraging activity per colony increases with nest number. The relationship between total prey input and foraging efficiency and number of nests per colony attains a plateau or even decreases after a certain colony size (four to six nests). This value agrees with the observed mean number of nests per colony in C. iberica. [source]

The ontogeny of foragwehaviour in desert ants, Cataglyphis bicolor

ECOLOGICAL ENTOMOLOGY, Issue 2 2004
Rüdiger Wehner
Abstract. 1. Individually foraging desert ants, Cataglyphis bicolor, exhibit short foraging lives (half lifetime, i.e. half-time of the exponential decay function: 4.5 days), in which they perform 3.7 ± 1.9 foraging runs per day. 2. During their short lifetime foraging period the ants increase the duration of their foraging round trips (up to 40.0 ± 24.6 min per run), the maximal distance of individual foraging runs (up to 28.2 ± 4.1 m), and their foraging success, i.e. the ratio of successful runs to the total number of runs (up to 0.70). 3. The parameter that increases most dramatically during a forager's lifetime is direction fidelity, i.e. the tendency to remain faithful to a particular foraging direction. 4. A model based on some simple behavioural rules is used to describe the experimental findings that within an isotropic food environment individual ants develop spatial foraging idiosyncrasies, and do so at a rate that increases with the food densities they encounter. 5. Finally, it is argued that in functional terms direction fidelity is related to the navigational benefits resulting from exploiting familiar (route-based) landmark information, and hence reduces round-trip time and by this physiological stress and predatory risk. [source]